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The Wireless Networking Question Roundup...
Which 802.11b-enabled PDA?
Kent Brewster asks: "I've retired my Palm 7 due to sudden lack of all-you-can-eat service and lots of free WiFi in the area. Right now, I'm looking at HP's iPAQ h5455, Toshiba's e750, Palm's Tungsten C, and Sharp's as-yet-to-ship Zaurus 5600. What I'm after is the best possible mobile Web experience first and PDA functions second. Opinions, please?"
802.11b Issues for Apartment Complexes? (Revisited)
johaninroseville asks: "I am in the planning stages to build a wireless network to provide an apartment complex with last mile Internet access. There are about six hundred units, but only one to two hundred interested people. For those curious as to the general layout of the apartments, here is an overhead picture.
My experience with radio frequencies, antennas, and especially how well radio waves can penetrate walls etc is rather limited. My game plan is to get a feed into the POP / MDF, and have a rather strong omni antenna mounted on the roof of that building. The coverage of that omni antenna will provide the links to the seven APs that will probably be needed, mounted on the rooftops around the complex. The seven IDFs, (or APs or what ever you want to call them) will each have a Point-to Point connection to the big omni antenna. Hardware used for the seven IDFs is planned to be: directional antenna (for link to omni in POP) connected to bridge, bridge connected to AP, AP connected to a sectored panel antenna that will provide end-user access (to their PCMCIA/PCI/CF/USB Cards, or to their access point).
My biggest questions are what antennas to use? What strength? How well can the radio waves from an omni antenna and/or a sector antenna penetrate multiple walls, if at all? How far can one of these antennas cover, and then penetrate walls?
I would appreciate any help at all in this matter. Maybe somebody has done something similar, or have some useful links."
Ask Slashdot last covered wireless apartment complexes about a year ago, and it would be interesting to note if any of the new technologies, introduced in the interim, will make this job any easier.
Outdoor Enclosures for 802.11b Equipment?
And finally, this question from ETEQ: "I need to operate a small amount of networking and wireless equipment (Router, Cable Modem, and 802.11 access point) in an outdoor setting, but the problem is that I live in Minnesota, where temperatures can drop far below freezing and stay that way for weeks (not to mention frequent heavy snow)... Are there any outdoor enclosures that can be purchased on a Home or SOHO budget?"
Most installations that I've seen use wires to the APs (often with Power-Over-Ethernet, to reduce wiring to a single cable). That way, you have fewer channel collisions, less overall wireless traffic, and significantly lower latency. You can put all of your wires in hallways, basements, and other "public" areas where you can work without going into people's apartments. Too ugly? Use drop ceilings and ceiling-mounted cable runs. Not to mention that it's far harder for a repirman to mess up a cheap 10/100 switch than an elaborate antenna array.
Also, think hard about setting up some sort of monitoring system. You want to have someone on the way to fix a failing AP before the angry calls come in.
Forward, retransmit, or republish anything I say here. Just don't misquote me.
Most of these features--crappy low-res cameras, SMS, e-mail, and simple PDA features--are not technological advances. What they represent is a sort of experimentation; phones are unlikely to get any smaller and still be usable, instead, designers are trying to determine what features are most wanted next to being able to make phone calls.
That said, the processor power in cellphones has remained fairly limited, while that in PDAs like the iPaq or the Zaurus is now greater than many of my still-useful desktops. PDAs are now running nearly-full-fledged operating systems like Windows Pocket PC or Linux. PDAs, just as phones, have to find their niche; designers must figure out what features make a PDA more desirable than just keeping notes and appointments, something which addmittedly has been somewhat supplanted by the phone.
The future is of course the merger of the two, not one beating the other in functionality, as you describe. Many PDAs can be used as phones, and many phones can be used as PDAs. To even make a distinction, or to claim that one category is advancing faster than another, is just silly. You consider a Treo a phone; many consider it a PDA. There will probably come a point, fairly quickly, where the only distinction is not whether it can make a call or not, but how big the screen is and how many added features it has.
You are to 2003 as Richard Nixon was to 1972.
Your current plan calls for a single distribution point, linked wirelessly to several secondary access points. With "1 to 2 hundred users", it looks like each of the 7 secondary access points will have to serve 30 users.
1) 30 users per secondary access point does not make for true broadband for any of the users, especially at peak times.
2) What kind of wireless link do you see between the distribution point and each secondary AP? This would have to carry enough bandwidth for 200 users. Doesn't sound feasible to me.
3) If your users are like typical home broadband users, then you don't want more than six to (max) twelve users per AP. Even with just six users per AP, at peak times they will experience less bandwidth than they would with DSL or Cable.
4) For two hundred users, you should build your wireless network around a solid wired Ethernet network for distribution. In other words, forget the "central" AP idea.
5) Install one AP for every 6 to 10 users (i.e. about 10 to 30 APs) and connect all of these APs to a wired (Ethernet) backbone running throughout the complex.
6) Think about how much wired capacity you'll need in order to provide broadband (2Mbps downstream) internet access to 200 users at peak times!
7) Require authentication using credentials (maybe NoCatAuth can help here), to ensure only paying tenants get access.
8) Combine MAC address checking with credentials-based authentication. This ensures (with some certainty) that each user pays for their own credentials.
9) Investigate solutions for throttling bandwidth to individual clients. No fair slowing down six paying customers because one of them is a pirate.
10) Do a detailed cost analysis to see the benefits of each possible solution: a) WiFi, b) Wired + WiFi (my proposal), c) Wired
Thoughts?
Forget about putting it on the roof. Getting a signal through multiple floors and ceilings will be tough. Fortunately every apartment should have a few rooms with a window. Mount it outside and tell everybody to put their antennas near the window that faces your AP. You don't have to get a wireless signal to every single point in the building, just to every apartment unit. The best place would be an interior courtyard.
This is what I do now. I have an open AP on a specially firewalled port, and it only allows web browsing through a proxy server. All other traffic is blocked, except for a few neighbors who know how to authenticate to my firewall and have less restricted access.
My AP is in the top of the house, with a nice omni antenna on the roof covering my neighborhood. I coordinate with several neighbors so our channels don't overlap. One neighbor in a shielded area has put up a yagi pointed at my omni, and gets a 2Mbps (really about 400kbps throughput) signal, which he repeats to several of his neighbors, using a linux box and 2 APs + 2 antennas. They buy me beers from time to time to pay me back. My neighbors are mostly geeks who want to experiment with wireless routing, and swapping emails between our servers without having to go through the internet.
Some evenings I see as many as 4 or 5 people connected. I feel this is the best use of my internet connection, because I'm providing a service which doesn't cost me much and certainly helps people sitting in the local cafe brun working on term paper research while downing a beer.
the AC
Hemos is like...sci-fi fans;he thinks technology is cool, but he hasn't bothered to understand the science it's based on
you'll have to make people swear not to use 2.4GHz cordless phones
600 people live there, only 150 want this internet access. Good luck telling 450 people to throw away their phones for something they will not even use, or want for that matter.